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[173.79.60.52]) by smtp.gmail.com with ESMTPSA id d75a77b69052e-5305402a7b7sm11260161cf.3.2026.09.03.20.18.05 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 03 Sep 2026 20:18:06 -0700 (PDT) Date: Thu, 3 Sep 2026 23:18:03 -0400 From: Gregory Price To: Qiqi Li Cc: linux-mm@kvack.org, Zhigang.Luo@amd.com, arun.george@samsung.com, balbirs@nvidia.com, brendan.jackman@linux.dev, yuzenghui@huawei.com, apopple@nvidia.com, alucerop@amd.com, matthew.brost@intel.com, akpm@linux-foundation.org, david@kernel.org, ljs@kernel.org, liam@infradead.org, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, corbet@lwn.net, skhan@linuxfoundation.org, gregkh@linuxfoundation.org, rafael@kernel.org, dakr@kernel.org, djbw@kernel.org, vishal.l.verma@intel.com, dave.jiang@intel.com, alison.schofield@intel.com, osandov@osandov.com, jannh@google.com, pfalcato@suse.de, jackmanb@google.com, hannes@cmpxchg.org, ziy@nvidia.com, pbonzini@redhat.com, osalvador@suse.de, joshua.hahnjy@gmail.com, rakie.kim@sk.com, byungchul@sk.com, ying.huang@linux.alibaba.com, kasong@tencent.com, qi.zheng@linux.dev, shakeel.butt@linux.dev, baohua@kernel.org, axelrasmussen@google.com, yuanchu@google.com, weixugc@google.com, yury.norov@gmail.com, linux@rasmusvillemoes.dk, longman@redhat.com, ridong.chen@linux.dev, tj@kernel.org, mkoutny@suse.com, sj@kernel.org, jgg@ziepe.ca, jhubbard@nvidia.com, peterx@redhat.com, baolin.wang@linux.alibaba.com, npache@redhat.com, ryan.roberts@arm.com, dev.jain@arm.com, lance.yang@linux.dev, usama.arif@linux.dev, xu.xin16@zte.com.cn, chengming.zhou@linux.dev, roman.gushchin@linux.dev, muchun.song@linux.dev, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, driver-core@lists.linux.dev, nvdimm@lists.linux.dev, linux-cxl@vger.kernel.org, linux-debuggers@vger.kernel.org, linux-fsdevel@vger.kernel.org, kvm@vger.kernel.org, cgroups@vger.kernel.org, damon@lists.linux.dev, linux-kselftest@vger.kernel.org, kernel-team@meta.com Subject: Re: [PATCH v5 25/36] mm/memory_hotplug: support N_MEMORY_PRIVATE node hotplug Message-ID: References: <20260720193431.3841992-1-gourry@gourry.net> <20260720193431.3841992-26-gourry@gourry.net> <6840c720-8cb7-46bb-a652-040c130a4427@huawei.com> <0334fe7d-d949-45f7-8914-3012cb11b740@huawei.com> Precedence: bulk X-Mailing-List: linux-cxl@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <0334fe7d-d949-45f7-8914-3012cb11b740@huawei.com> On Fri, Sep 04, 2026 at 09:05:39AM +0800, Qiqi Li wrote: > On 8/17/2026 8:49 AM, Gregory Price wrote: > > It would need to be reserved, and you could use numa emulation but > > that's clunky. I have an RFC for exactly this issue - though i haven't > > pushed it further yet. > > > > https://lore.kernel.org/all/20260610014517.253609-1-gourry@gourry.net/ > > Hi Gregory, > > Sorry for the late reply. > > I took a look at the exclusive-node RFC. The approach looks useful for > device-backed private memory without a firmware-described NUMA node. > Thanks for the pointer. > > We are currently looking into the private-node and CRAM design as a > whole. I noticed that CRAM was not included with the v5 series, and saw > that others were also interested in a v5 version. > > If you already have a CRAM branch or patches based on v5, even if they > are still work in progress, would you mind sharing them? It would be > very helpful for us to continue testing the overall design. > I dropped it off because it was starting to become unwieldly, but i am continuing to maintain a branch on my github: https://github.com/gourryinverse/linux/commits/scratch/gourry/cramtest/cram_72/ I have not posted a new version in some time and it has been reworked significantly in the past few months - but I plan to talk about this particular branch and the tests I've run with it at the device memory LPC micro-conference. I validated this branch against most in-tree (relevant) filesystems for the page-cache extension, but I imagine the anon-only version subset is the more immediately interesting for upstream development. I may include the anon-only version in v6, but I've been a bit busy shoring up the base private memory node core and implementing kernel selftests and LTP tests to ensure there's no userland api regressions. I hope to get something out later this month. ~Gregory